Friends of Dyke Marsh is a volunteer group dedicated to preserving, restoring and enhancing Dyke Marsh, a freshwater tidal marsh in Fairfax County on the Potomac River just south of Alexandria, Virginia. The Dyke Marsh Wildlife Preserve is administered by the National Park Service.

What Is Dyke Marsh?

The Dyke Marsh Wildlife Preserve is a freshwater, tidal marsh on the Virginia side of the Potomac River in Fairfax County. It is a unit of the George Washington Memorial Parkway, U.S. National Park Service. For more information, visit the NPS website at www.nps.gov/gwmp.

Keen observers have watched the parents and two young barred owls (Strix varia) in Dyke Marsh this spring, 2020. Ed Eder captured the two owlets doing mutual preening on April 17 and Ed reported that they usually stick close together.

Barred owls are known for their haunting, baritone night call, “who cooks for you, who cooks for you-all.” They get their name from their “bars” or striped plumage. Generally, they roost during the day and hunt at night. Adults are around 21 inches in length and a little over a pound in weight. They tend to be in older forests, but are highly adaptable to varied habitats, including mixed forests and disturbed areas. “Barred owls are the opportunists of the owl world,” wrote Leigh Clavez in The Hidden Lives of Owls.

Dyke Marsh has had another first this spring, 2020 -- several sightings of a yellow-headed blackbird (Xanthocephalus xanthocephalus). In fact, it is a record for the George Washington Memorial Parkway according to Brent Steury, the Parkway’s Natural Resources Program Manager.

The beautiful blackbird in Dyke Marsh is a male with a stunning yellow head, black body, yellow breast and white markings on its wings. Females and immature males are brown-black with reduced yellow on the face, throat and brow. These birds typically nest in the West and Midwest in colonies, often alongside red-winged blackbirds in bullrushes or cattails. They forage on insects, grain and wet seeds.

An osprey (Pandion haliaetus) was a victim of a bald eagle (Haliaeetus leucocephalus) attack on Sunday afternoon, March 22, 2020. The bald eagle may have attacked the osprey trying to defend his or her territory or because of what is called kleptoparisitism when one species steals food from another. The osprey came to the ground after the attack and was stuck in some bushes. FODMers Rich Rieger and Sherman Suter extracted the bird and Rich wrapped it up in his coat. Despite some bleeding, the osprey settled down and Rich placed the bird on a picnic table. After a moment, the osprey took flight, seemed normal to the human eye and landed in the top of a tree.

On March 20, 2020, around 7 a.m., several FODMers observed that the water in west Dyke Marsh and an unnamed stream flowing in the marsh was neon green. This part of the marsh is around 15 to 20 acres and west of the George Washington Memorial Parkway.

We contacted local, state and National Park Service officials. Fairfax County sent wastewater and hazardous materials staffers, the Virginia Department of Environmental Quality sent pollution experts and the National Park Service sent a staffer, all to inspect the site.

On March 1, 2020, Shenandoah National Park biologist Rolf Gubler described the peregrine falcon (Falco peregrinus) restoration project to a packed room of 80 enthusiasts. This project in the park is a partnership of the National Park Service (NPS), William and Mary College’s Center for Conservation Biology (CCB), the Virginia Department of Game and Inland Fisheries (DGIF) and the Virginia Department of Transportation (VDOT).

In early January 2020, FODMer Ed Eder photographed a rare visitor flying over Dyke Marsh, Ross’s goose (Anser rossi), which National Park Service biologist Brent Steury said was a new record sighting for the George Washington Memorial Parkway.

This goose is white with black wingtips and considered the smallest of the "light" or snow geese. Ross's goose has a short neck, rounded head and a stubby bill with no "grin patch" seen in its larger cousins due to their curved tomium, the cutting edge of the bill, Ed explained. More mature birds, particularly males, have warty gray tubercles at the base of their bills, said Ed.

On December 2, 2019, the Fort Hunt Herald newspaper published an interview with FODM President Glenda Booth, in which she discusses the marsh restoration project, emerald ash borer infestation, the native plants project, bald eagles and more. Visit here to read the entire article.

On November 13, 2019, at FODM’s quarterly meeting, Dr. Sally Valdes outlined several ways that climate change is adversely affecting wildlife. Introducing the topic, she said that carbon dioxide and other greenhouse gas emissions have risen to levels unprecedented in the last 800,000 years. Carbon dioxide concentrations have been tracked continuously at the Mauna Loa Observatory in Hawaii since 1958 and the trend has been steadily upward, from about 315 parts per million (ppm) to 414 ppm in the spring of 2019.

On October 11, 2019, FODM volunteers and National Park Service staff put in 400 more native plants in the native plant restoration area in Dyke Marsh, a .65-acre plot on the west side of the Haul Road trail. The group planted riverbank wild rye (Elymus riparius), New York ironweed (Vernonia noveboracensis), wild rice (Zizania aquatica) and deer tongue (Dichanthelium clandestinum (syn. Panicum clandestinum)).

FODM Board of Directors’ member Deborah Klein Hammer saves bats and is featured in a September 16, 2019, article in “DCist” here.

Deborah studies Brazilian freetail (Tadarida brasiliensis) and Seminole bats (Lasiurus seminolus) in Dyke Marsh. Around 2013, a Brazilian free-tailed bat came into care of the Save Lucy Campaign (www.savelucythebat.org/), an organization devoted to rehabilitating injured and orphaned bats and educating the public about the importance of bats.

FODM Membership Meetings

We have rescheduled our May 19 meeting for September 8. See below. Given the uncertainty posed by the coronavirus pandemic, we may have to make some changes. Check here and our Facebook page for updates.

Coming Events

On September 8 at 7:30 p.m., Dr. Christian Jones of George Mason University’s Potomac Science Center will give a presentation on wetlands types, trends, ecology and conservation at the Huntley Meadows Park Visitor Center, 3701 Lockheed Boulevard, Alexandria, VA 22306. An informal social will start at 7 p.m. Free.

Bird Walks Canceled Through June 10

*** NOTICE ***

In light of risks related to the coronavirus, the Friends of Dyke Marsh have canceled Sunday morning bird walks at Dyke Marsh starting March 15 and effective through June 10. We hope to resume walks on June 14. Check back here and our Facebook page for information on the future schedule.

Support FODM

Your contribution will help us preserve and restore Dyke Marsh and support special programs and studies. Thank you.

Support Dyke Marsh with Your Purchases

Amazon.com will donate .5 percent of the price of your purchases to the Friends of Dyke Marsh if you shop through smile.amazon.com. Click on the link and sign into your account or create an account.

Like Us on Facebook!

FODM is on Facebook. If you are already a Facebook member, just log in to your Facebook page and search for "Friends of Dyke Marsh". Or, click this icon and then "like" us:

Bienvenidos!

The Friends of Dyke Marsh extend a welcome to all of our friends. Click here for an invitation to the Dyke Marsh Wildlife Preserve in Spanish, which we hope will make Spanish-speaking visitors feel welcome. We hope to see you soon.

Event

Wintering Waterfowl

Tundra swan (Cygnus columbianus) Photo by Cathy Ledec.

FODM President Glenda Booth has an article in the January 2020 Zebra newspaper on waterfowl on the Potomac River in winter. Read the article here.

Loggerhead Shrikes

Sergio Harding banded the shrikes with a red band.

FODM President Glenda Booth published an article in the May-June 2018 Virginia Wildlife magazine, titled, “What’s Going on with the Butcher Bird? Visit the website here. Sightings of this bird in Northern Virginia are rare.

Water Chestnut

Water chestnut. Photo from MISC, Maryland Invasive Species Council.

Help Stop the Spread of a New Species of Water Chestnut

Be on the lookout for a new species of water chestnut (genus Trapa) (http://mdinvasives.org / iotm/june-2018/) found in the Potomac watershed, Trapa bispinosa Roxb. var. iinumai Nakano. It has been spreading since 1995 and is floating aquatic vegetation growing over the surface of a pond, lake or other fresh waterbody.

This species is identified by the seed cases having two spines instead of four found on Trapa natans. Report all invasive aquatic species to the US Geological Survey’s Nonindigenous aquatic species website (https://nas.er.usgs.gov / SightingReport.aspx).

Water chestnut (an annual) sprouts in May, spreads over the water surface and then flowers and fruits by July. It drops seeds all season until it senesces after a hard frost. To stop the spread, management by harvesting the plants by early July is very successful in eradicating the plants, but it may take several years of effort, if some seeds fall before the plants are harvested or lay dormant in the current year and sprout in a later year.